NoIBExample.swift

@objc protocol ViewDelegate {
    func pressedButton()
}

class View: UIView {

    let button = UIButton()
        .stylePrimary(fontSize: 14)
        .layout(width: 50, height: 30)

    init() {
        super.init(frame: .zero)
        layout(center: button)
    }

    weak var delegate: ViewDelegate? = nil { didSet {
        button.addTarget(delegate, 
            action: #selector(ViewDelegate.pressedButton), 
            for: .touchUpInside
        )
    } }
}

class ViewController: UIViewController, ViewDelegate {

    init() { super.init(nibName: nil, bundle: nil) }

    override func loadView() {
        view = View() <== { $0.delegate = self }
    }

    func pressedButton() { /* react to button press */ }
}